Hmmm well I have always had dogs from pups so recall has never been an issue whereas now with Bella who is 5 and has an uncertain past (she has the scars to prove something has happened) however she cannot talk.
So I have done off lead once since having her I must admit I will not do it again soon because after over 3/4 of my life having and walking dogs I realised rescue (adult) is different she had not got that "link/bond" with me.
In her life I was then one of many humans possibly passing through.
So I was lucky we were without temptations when we tried the off lead (being a staff I went dog free) however not secure.
So I have really thought about it and decided to go to basics like you would with a pup "getting to know each other" but remember that she comes with pre programmed reactions to certain situations hence we have not gone off lead since then.
She is road walked four times a day. Some just walking and seeing her reaction to situations (she is scared of thunder fireworks) one reactive to people/bikes/pushchairs/wheelchairs/scooters......but this is on lead and under control of the lead.
Off lead would be another ball game...... on all our daily walks I get her attention with a small treat (kibble from her daily allowance) I also do this training before her tea
. I speak I just use the word "come" even if she is 1/2" from me - she stops turns looks at me expecting a treat which now is often substituted with a pat/fuss rather than a treat.
And in the last 2 weeks or so she has started to step into family life.....rather than watch from outside. She leans against me now and searches me out rather than watch from a distance. She has come to understand the routine....and maybe that she is home. Watching her settle in makes me realise why people have rescue/adults. The pro's outweigh the cons. But the cons are more apparent than with a pup who is mouldable.
She also sits at gutters and when I stop to speak to people. It is all part of encouraging her to trust and listen to me and nothing will happen when she is with me - she does not need to react to other dogs or anything I can control the situation.
So off lead I am happy to have her stay on lead all her life. Although I do have a long lead about 10m but it takes a bit of getting used to however you do not have to use all of it I reduce it up to 2/3rds with a "tie-it/" but I am going to start using that on our "country early morning day off walks" letting her have a little freedom and how the land lies- but I do prefer that to an extendable lead - they have no place in a Stafford(strong dog life) who is not already trained. They have there place with dogs who are trained but not I do not think for dogs who are reactionary to anything. In my opinion.
But you could try doing off lead training as I did with mine as pups.....secure space try a tennis court and make sure you can get their attention in a boring space before introducing the wide world of temptations.
You could try in the garden calling him then treating him with food or a tug game or something then your OH calling him and again treat then you call him. But stop before he gets bored maybe twice each call him in for his dinner make him sit/wait so he is learning you want him he comes regardless of his opinon
and good luck. And in essence you already have him off lead in the house - use that as a training ground.....dogs are creatures of habit and routine so make it a routine he obeys you. But in a non confrontational way. Its still early days